Smith, a professor in the university’s materials science and engineering department, was arrested Saturday afternoon on possession of child pornography charges shortly after disembarking the Delta Airlines flight.

Smith was sitting in first class when a passenger seated behind him saw the images and became concerned. The passenger took a cellphone picture of what Smith was doing, then alerted a flight attendant. The passenger also emailed a relative about the situation and asked that person to contact police, and the person did, Prosecutor Erik Bennett said.

Bennett said that Smith tried to erase pictures of what appeared to be pre-teen girls engaged in sexual acts after a flight attendant told him to turn off his computer.

The recently divorced Smith was met at the gate by state police, who asked for and were granted permission to view the contents of the laptop. Investigators allege they found several images of nude or nearly nude children, including girls apparently as young as 6 years old.

"Child pornography is a form of child sexual abuse — nothing less," state police spokesman David Procopio said in a statement. "Those who possess it — a crime unto itself — foster an evil network that sexually abuses and exploits children irreparably."

The judge in East Boston District Court also ordered Smith to have no unsupervised contact with children under 16, to surrender his passport and to refrain from using the Internet except for business purposes if he makes bail.

Smith’s lawyer argued for lower bail, saying his client had no criminal record and had been at the university for 14 years.

He was in Boston to attend the Materials Research Society’s weeklong fall meeting and exhibit, scheduled to start Monday.

The university placed Smith on administrative leave pending the outcome of the case.

"Professor Smith deserves a full and fair investigation into this issue," a university statement said. "The University of Utah, however, has no tolerance for the viewing or possessing of child pornography by any of its employees, regardless of where it occurs."

Smith will be fired if convicted, the statement said.

The investigation is ongoing and Smith is scheduled to return to court on Dec. 27, authorities said.